Evaluation of Chicken Embryo Extract and Egg Yolk Extract As Alternatives to Basic Cell Culture Medium Supplement

Background: Fetal calf serum (FCS), an existing cell culture supplement, is effective but has several drawbacks, including being expensive, requiring a lengthy process of production, and requiring a hard currency. With this in mind, we planned to evaluate chick embryo extract and egg yolk extracts in cell culture as alternatives to fetal calf serum (FCS).

Methods: Specific pathogen-free eggs were purchased from the National Veterinary Institute, Bishoftu, Ethiopia, and incubated in a humidified incubator at 37 °C for 11 days. Egg yolk extract (EYE) and chick embryo extract (CEE) were collected after the egg was opened with caution not to destroy the yolk sack or the chick embryo itself. Chick fibroblasts and Vero cells were cultured in minimum essential medium (MEM) supplemented with egg yolk extract or chick embryo extract at ratios of 0:10, 1:9, 2.5:7.5, and 5:5% fetal calf serum.

Results: Fibroblast cell attachment was better in media supplemented with 5% CEE and 5% FCS. The confluency was also greater than 50% at this concentration. Vero cells cultured with 5% CEE and 5% FCS also exhibited very good cell attachment and a confluency of up to 70%. Viability and confluency were also observed at 5%:5% ratios of 50 and 70%, respectively.

Conclusion: This investigation evaluated these two extracts as cell culture supplements and revealed promising results as alternatives to fetal calf serum. The limitation of this study is that it only used two cell types and additional cell lines, and different ratios should be tested. With the above findings, further research using different cell lines, ratios and conditions is warranted.